Use of cataract surgery in urban Beijing: a post screening follow-up of the elderly with visual impairment due to age-related cataract

Prevalence and causes of vision loss in East Asia in 2015: magnitude, temporal trends and projections

BACKGROUND

To determine the prevalence and causes of blindness and vision impairment (VI) in East Asia in 2015 and to forecast the trend to 2020.

METHODS

Through a systematic literature review and meta-analysis, we estimated prevalence of blindness (presenting visual acuity <3/60 in the better eye), moderate-to-severe vision impairment (MSVI; 3/60≤presenting visual acuity <6/18), mild vision impairment (mild VI: 6/18≤presenting visual acuity <6/12) and uncorrected presbyopia for 1990, 2010, 2015 and 2020. A total of 44 population-based studies were included.

RESULTS

In 2015, age-standardised prevalence of blindness, MSVI, mild VI and uncorrected presbyopia was 0.37% (80% uncertainty interval (UI) 0.12%-0.68%), 3.06% (80% UI 1.35%-5.16%) and 2.65% (80% UI 0.92%-4.91%), 32.91% (80% UI 18.72%-48.47%), respectively, in East Asia. Cataract was the leading cause of blindness (43.6%), followed by uncorrected refractive error (12.9%), glaucoma, age-related macular degeneration, corneal diseases, trachoma and diabetic retinopathy (DR). The leading cause for MSVI was uncorrected refractive error, followed by cataract, age-related macular degeneration, glaucoma, corneal disease, trachoma and DR. The burden of VI due to uncorrected refractive error, cataracts, glaucoma and DR has continued to rise over the decades reported.

CONCLUSIONS

Addressing the public healthcare barriers for cataract and uncorrected refractive error can help eliminate almost 57% of all blindness cases in this region. Therefore, public healthcare efforts should be focused on effective screening and effective patient education, with access to high-quality healthcare.

Re-engineering the Hong Kong Quality of Life Questionnaire to Assess Cataract Surgery Outcomes

PURPOSE

To assess psychometric properties of the Hong Kong Quality of Life Questionnaire (HKQ) using Rasch analysis and use it to assess cataract surgery outcomes.

METHODS

The HKQ was interviewer administered to participants at baseline (preoperative) and 12 months of follow-up (postoperative). Rasch analysis was used to assess and improve psychometric properties of the HKQ using the preoperative data. The responsiveness of the HKQ was assessed on the stacked preoperative and postoperative data, reported with the effect size.

RESULTS

One hundred ninety-nine participants (median age: 72 years; interquartile range: 65 to 78 years) with cataract completed the HKQ at the preoperative assessment. There were more women (58%) and most of the participants had bilateral cataract (83.9%). Nearly half of the participants had undergone surgery in one eye (45.2%) followed by bilateral surgery (38.7%). Psychometric assessment guided by Rasch analysis resulted into a 15-item HKQ with promising psychometric properties including adequate measurement precision (2.09), no misfitting items, near perfect targeting (-0.05), unidimensionality, and with no evidence of item bias. For those who completed the HKQ (n = 82, 41.2%) at the 12-month follow-up visit, all groups demonstrated statistically significant gains in the HKQ scores, with the highest gain in participants who had undergone bilateral surgery (effect size: 2.61).

CONCLUSIONS

The 15-item HKQ was valid and psychometrically sound and might be a highly responsive instrument to measure cataract surgery outcomes in China. This study demonstrated that cataract surgery significantly improves quality of life in the Chinese population. [J Refract Surg. 2018;34(6):413-418.].

Assessment of Cataract Surgery Outcome Using the Modified Catquest Short-Form Instrument in China

Purpose

To assess cataract surgery outcome using the Rasch scaled Chinese version of the Catquest short-form.

Methods

The Chinese translated and culturally adapted version of the Catquest-9SF was interviewer-administered to patients, pre and post cataract surgery. Rasch analysis was performed on the baseline data to revise the Catquest. For the surgical outcome assessment, we stacked pre- and post-surgical Catquest data to demonstrate improvement in visual function scores and responsiveness of the instrument to cataract surgery.

Results

A total of 247 cataract patients (median age, 70 yrs; male 51.0%) completed the Catquest 9SF at baseline.The Catquest-9SF possessed adequate measurement precision of 2.15. No disordering of response categories were observed and all the items perfectly fit to the Rasch model except item 7 (outfit >1.5). A slight reduction in precision was observed after removing misfitting item 7 (Catquest-8SF-CN), but the precision value was well above the acceptable value of 2.00. Notably, the instrument was well targeted (mean person location 0.30), demonstrated no evidence of multidimensionality and DIF. At 12 months post-surgery, 74 (30%) patients came for follow-up and completed the Catquest. There was a significant improvement in the Catquest scores post cataract surgery with a considerably large effect size.

Conclusion

The Catquest-8SF-CN demonstrated promising Rasch based psychometric properties and was highly responsive to cataract surgery.